Life support system

ABSTRACT

A lightweight life support system for extravehicular space activity which may be either mounted in a back-pack or integrated into a protective suit. Two subsystems are provided to maintain the suit inhabitant in his environment. The first subsystem is an open loop, single pass ventilation system, having a high-pressure oxygen and mixed gas storage which is maintained within lightweight, stress-limited pressure vessels. A breathing bag cooperates with the open loop system to meet the peak respiratory demands. The second subsystem comprises a protective suit having a duct network, a liquid pump, and a sublimator-heat exchanger which in combination provide a suitable thermal condition.

United States Paten [451 Jan. 18, 1972 Curtis [54] LIFE SUPPORT SYSTEM[72] Inventor: Daniel L. Curtis, Manhattan Beach, Calif.

[73] Assignee: Granted to National Aeronautics and Space Administrationunder the provisions oi 42USC 2457(d) [22] Filed: Jan. 29, 1968 [2]]Appl. No; 701,244

[52] U.S. Cl.... ..l28/l42.5, 128/402, 2/2.1 [51] Int. Cl. ..A62b 7/02[58] Field of Search ..i28/l42.2, 142.4, 142.5, 142.3, 128/400, 402;62/259, 223; 2/2, 2.1, 2.5

{56] References Cited UNITED STATES PATENTS 3,117,426 1/1964 Fischer etal. ..62/223 Primary Examiner-Richard A. Gaudet AssistantExaminer-Gerard F. Dunne Attorney-Marvin F. Matthews, Edward K. Fein andJohn R. Manning [57] ABSTRACT A lightweight life support system forextravehicular space activity which may be either mounted in a back-packor integrated into a protective suit. Two subsystems are provided tomaintain the suit inhabitant in his environment. The first 9 Claims, 4Drawing; Figures PAIENTEDJAN 181972 SHEET 2 [IF 2 LIFE SUPPORT SYSTEMORIGIN OF THE INVENTION The invention described herein was made in theperformance of work under a NASA contract and is subject to theprovisions of Section 305 of the National Aeronautics and Space Act of1958, Public Law 85-568 (72 Stat. 435; U.S.C. 2457).

FIELD OF THE INVENTION This invention relates to a life support systemand more particularly to a novel open loop life support subsystem whichincludes a breathing bag as a reservoir.

DESCRIPTION OF THE PRIOR ART Generally, life support systems may bedivided into three categories, namely, closed loop, semiclosed loop andopen loop systems. The closed loop system is a highly complex systemwhich leads inevitably to low inherent reliability, thus necessitatinghigh maintainability. Furthermore, a closed loop system requires arather bulky CO arrangement including a contaminant absorbent, and anelectrical circulation fan, which in combination inherently addsadditional weight that must be carried by an individual. The semiclosedloop system is also quite complex because of the reprocessing system andthe oxygen flow rate is typically four times greater in the semiclosedloop system than in the closed loop system. Thus, roughly four times asmuch oxygen is required for a mission of the same duration.

On the other hand, the open loop single pass system of the presentinvention does not require recirculation of the breathing gas and thereis no need for a carbon dioxide absorber or a ventilation fan and itsassociated battery. In addition, the open loop system is more compactand lighter in weight, thus the user may move around with greaterdexterity and ease.

Accordingly, it is an object of the present invention to provide a lifesupport system having an open loop single pass ventilation flow.

It is a further object of the present invention to provide an improvedlife support system utilizing an oxygen and mixed gas supply which iscirculated in light weight stress-limited pressure vessels.

It is a still further object of the present invention to provide animproved life support system which may be either mounted in a backpackor integrated into a protective suit.

It is another object of the present invention to provide an improvedlife support system having a pulse pump and a sublimator-heat exchangerto ensure thermal control of a liquid coolant gannent.

It is still another object of the present invention to provide animproved life support system wherein a breathing bag serves as a gasreservoir to meet the peak respiratory demands from an averagerespiratory supply source.

SUMMARY OF THE INVENTION In accordance with the objects set forth above,the present invention provides a lightweight life support system forextravehicular space activity which may be either mounted in a backpackor integrated into a protective suit. The life support system comprisestwo subsystemsan open loop ventilation subsystem to meet the ventilationrequirements and a thermal control subsystem to maintain suitablethermal conditions. The first subsystem is an open loop, single passventilation system, having a high-pressure oxygen and mixed gas storagewhich is maintained within lightweight, stress-limited pressure vessels.A breathing bag cooperates with the open loop system to meet peakrespiratory demands. The second subsystem comprising a protective suithaving a duct network, a liquid pump, and a sublimator-heat exchanger incombination provides a suitable thermal condition.

BRIEF DESCRIPTION OF THIE DRAWINGS Additional objects, advantages, andcharacteristic features of the present invention will become readilyapparent from the following detailed description of preferredembodiments of the invention when taken in conjunction with theaccompanying drawings in which:

FIG. I is a block diagram of a life support system in accordance withthe present invention;

FIG. 2 is a front view of an astronaut shown within an integrated lifesupport system in accordance with the present invention;

FIG. 3 is a side view of an astronaut shown within an integrated lifesupport system in accordance with the present invention; and

FIG. 4 is a perspective view of a backpack of a life support system inaccordance with the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to FIG. 1, thereis shown one of the embodiments of a life support system 10in accordancewith the principles of this invention. The life support system 10comprises two subsystems-an open loop ventilation subsystem to meetventilation requirements and a thermal control subsystem to maintainsuitable thermal conditions. Some of the components in the life supportsystem ll) are utilized in both subsystems, for example, a pulse pump25. The open loop ventilation subsystem will be discussed first.

Normally, an open loop ventilation subsystem requires that the gas flowto the system inhabitant be controlled by the inhabitants breathingpattern. This approach, while functional,

t is considered to be undesirable under certain conditions, for

example, where the lungs act as a pump, fatiguing problems areexperienced at metabolic rates higher than approximately 1,100B.t.u./hr. A preferred method of meeting the ventilation requirements ofthe inhabitant is to provide a gas flow at a continuous rate. The methodpractices in accordance with the principles of this invention is toprovide a continuous bleed of gas from a compressed gas source 19 atapproximately I c.f.m. However, it must be recognized that while anaverage flow of l c.f.m. matches the average respiratory demand at ametabolic rate of 1,600 B.t.u./hr., the average demand during inhalationis roughly 2 c.f.m. with peak demands as high as 2.5 c.f.m. Thus, asimple gas flow system supplying l c.f.m. on a continuous basis istherefore inadequate as it does not provide for the complete cyclicaldemand of breathing. Therefore, in order to meet the ventilationrequirements of the suit inhabitant at all times, a breathing bag 13 isincorporated within the open loop ventilation subsystem to act as areservoir to meet peak demand periods. While the invention has beendescribed with particular reference to a compressed gas source operatingat approximately 1 c.f.m., it should be understood that the prac tice ofthis invention is not necessarily limited thereto, but may be practicedto equal advantage utilizing other c.f.m. rates depending upon therequirements of a particular opera tion.

To meet the necessary respiratory ventilation requirements of theastronaut, the compressed gas source 19 is provided. The use of the termgas" is understood to include any combination of gases which may serveto provide ventilation to the astronaut. Throughout this disclosure, thesystem inhabitant will be referred to as an astronaut; however, the lifesupport system l0 may be used in other suitable environments. Aregulator 20 is adapted to receive the gas from the gas source 19 vialine 21 at approximately 3,500 psi. A gas pressure gauge 20a is providedas shown. A pneumatic line 23 connects the output of the regulator 20 toa manual control valve 22. The manual control value 22 allows theastronaut to adjust the rate of flow of gas out of the regulator 20. Theoutput of the regulator 20, at approximately 15 p.s.i., is then fed to apulse pump 25 via a pneumatic line 26. The gas is utilized in the pulsepump 25 as a pumping fluid" to actuate the flow of a liquid coolantthrough a liquid coolant garment 28. The operation of the pulse pump 25will be explained in more detail in a later discussion of the thermalcontrol subsystem. The gas is routed through the pulse pump 25 and tothe breathing bag 13 via a pneumatic line 27 and an input 13a.

A protective suit 11 including a helmet 12 are shown schematically inFIG. 1. The protective suit 11 may be of any suitable imperviousmaterial capable of protecting an individual from atmospheric pressures.Presently, protective suits of either the hard or soft variety areemployed depending upon the particular mission. The hard suit type isusually made of aluminum sheet formed into the shape of a human body andhaving flexible joints where necessary. The soft type is normally madeof a fabric that is capable of maintaining a pressurized conditionrelative to the outside environment. The helmet 12, which is attached tothe protective suit 11, may be of any suitable type, for example, onehaving a hemispherical polycarbonate pressure visor, two movableovervisors and a protective visor cover. Normally, the pressure visorwould be constructed of sufficient thickness to resist mechanical andmicrometeoroid impacts.

The breathing bag 13 is physically located between the protective suit11 and the chest and back area of the astronaut. The breathing bag 13has an input 13a and an output 13b. The output 13b of the breathing bag13 is adapted to allow gas to be fed into the helmet 12. Acommunications system 15 including an antenna 16 is shown connected tothe helmet 12 via line 17 in order to provide the astronaut with acommunications system. A one-way check valve 18 is shown connected tothe helmet 12 to provide an outlet for the expired gas of the astronaut.

Since the protective suit 11 provides a rigid torso section in the areaof the astronaut's chest and back, the breathing bag will be compressedand inflated in response to the breathing pattern established by theastronaut. During inhalation, the chest of the astronaut will compressthe breathing bag 13, thus allowing additional gas to be available inthe oral-nasal region. During exhalation, the breathing bag 13 isallowed to be reinflated by the continuous gas stream into the input13a. Any expired gas routed to the helmet l2 aids in flushing expiredgas from the region of the helmet 12. Thus, the breathing bag 13 servesas an intermediary reservoir allowing peak respiratory demands to be metfrom an average supply source having a c.f.m. capacity less than halfthe peak requirements.

The expired gas of the astronaut flows from the helmet 12 via the checkvalve 18. This expired gas will be cooled and dehumidified and thenrouted back into the protective suit 11 where it will assist to maintainthe body of the astronaut in a comfortably dry condition. The expiredgas first travels to a gas cooler 37 via a pneumatic line 42. Theexpired gas is cooled in the gas cooler 37 and then travels to a waterseparator 38 via a pneumatic line 43. The water separator 38 may be astandard elbow water trap which will condense the respiratory watervapor from the gas. The condensed water is routed to a water storageunit 34 via a line 39. The water storage unit 34, which is primarilypart of the thermal control subsystem, provides water to asublimator-heat exchanger 33 to initiate the sublimation process inaddition to storing the aforementioned condensed water. A bladder 35prevents the condensed water from going to the clean water portion ofthe water storage unit 34. The cooled, low-moisture content gas is thenallowed to enter an input 41 of the protective suit 11 viaa line 40.This cooled, low-moisture content gas is routed from the input 40 to thebody extremities, that is. the arms and legs, of the astronaut viasuitable ducts, shown schematically as 4lathrough d. The gas thencirculates over the body of theastronaut and is expelled from theprotective suit 11 at an output 44. Preferably, the output 44 is locatedin the chest area of the protective suit 11 to ensure that the cooled,low-moisture content gas maintains substantially the entire body of theastronaut in a comfortably dry position. The continual venting of theexpired gas from the output 44 of the protective suit 11 ensures theoperation of the open loop ventilation subsystem,

thus, there is no need to require a blower to maintain circulation ofthe ventilation gas.

in addition to the ventilation subsystem described, the life supportsystem 10 includes a thermal control subsystem. The thermal controlsubsystem comprises the liquid coolant garment 28, the sublimator-heatexchanger 33, a pump accumulator 29, the water storage unit 34, andassociated components. A liquid coolant supply which is stored in thepump accumulator 29 travels in the closed loop 31 in a counterclockwisedirection as shown. The thermal control subsystem ensures adequatecooling of the body of the astronaut.

The liquid coolant garment 28 may be of any suitable type, for example,the type described in the Alan S. Penfold US. Pat. application, Ser. No.376,745, assigned to the same assignee of this invention. The liquidcoolant garment 28 is designed to cover the body areas extending fromthe knees to the elbow, including the back of the neck and skull.Normally, elastic material is employed in the arm and leg areas tomaintain proper pressure contact of the garment with the skin. The pumpaccumulator 29, including a diaphragm 30, ensures that an adequateliquid coolant supply is available to flow through the liquid coolantgarment 28.

As discussed earlier, pulse pump 25 is utilized to provide a smooth flowof liquid coolant through the liquid coolant garment 28. The pulse pump25 may be of the type shown in the Daniel L. Curtis US. Pat.application, Ser. No. 488,367, assigned to the same assignee of thisinvention. The pulse pump 25 is shown schematically with the properinlets and outlets. Basically, the pulse pump 25 comprises a pump casing51 having an inlet port 51a and an outlet port 51b, through which thegas from the compressed gas source 19 may flow, and a flexible wallchamber 50, which may be a tubular membrane, positioned within the pumpcasing 51 having an inlet port 510 and an outlet port 51b. The liquidcoolant from the pump accumulator 29 is fed to the inlet port 50a,through the flexible wall chamber 50, and then out of the outlet port50b to the liquid coolant garment 28.

In the operation of the pump 25, when the liquid coolant fills theflexible wall chamber 50, the chamber becomes fully distended and coversthe outlet port 5012 thereby inhibiting the flow of the gas through thepump casing 51 so that the pressure of the gas within the casing willincrease. The flexible wall chamber 50 is thereby inflated to itsmaximum dimension, as limited by the internal wall of the pump casing51. Thus, an effective gas seal is formed by the flexible wall chamber50 against the inner wall of the pump casing 51 and gas flow into thepump from the constant pressure source is trapped causing the gaspressure in the pump 25 to increase. As the gas pressure increases itbecomes greater than the pressure of the liquid coolant, so as to causethe flexible wall chamber 50 to collapse and pump the liquid coolantcontained therein in a smooth motion from one end of the pump casing 51to the other. The gas seal is broken upon the collapse of the flexiblewall chamber 50, allowing the gas to exit the pump through the outletport 51b. The sudden drop in gas pressure within the pump, as the gasescapes through the outlet port 51b, results in the pressure of theliquid coolant being greater than the gas pressure and allows the liquidcoolant to enter the flexible wall chamber, forcing it to reexpand.Thus, the pumping cycle is initiated again.

A pneumatic line 27a is connected between the pneumatic line 27 and theinlet port 53 of the pump accumulator 29 in order to provide a pressurehead on the liquid coolant in the pump accumulator 29. The pressure headis maintained by the diaphragm 30, which separates the gas from theliquid coolant.

Also included within the closed loop 31 is a diverter valve 32. Aportion of the liquid coolant from the liquid coolant garment 28 flowsdirectly to the diverter valve 32 via line 31a, while another portion isdiverted via line 31b through the sublimator-heat exchanger 33. Theliquid coolant divertedv through the sublimator-heat exchanger 33 willbe cooled. Thus, the temperature of the liquid coolant out of thediverter valve 32 that is ultimately fed to the liquid coolant garment28, may be regulated. The diverter valve 32 allows the astronaut toadjust the flow of liquid coolant through the heat exchanger portion ofthe sublimator-heat exchanger 33. if the body surface temperature of theastronaut is too warm, the diverter valve 32 may be adjusted to allowadditional liquid coolant to flow through the sublimator-heat exchanger33. On the other hand, if his body surface temperature is too cool, theastronaut may adjust the diverter 32 to allow less liquid coolant toflow through the sublimator-heat exchanger 33.

The sublimator-heat exchanger 33 is typical of the class of heatdissipation devices that are used in a vacuum for the purpose ofrejecting system heat to the vacuum such as the type disclosed in thecopending Daniel L. Curtis US. Pat. application, Ser. No. 825,812, filedMay 19, 1969 and assigned to the same assignee of this invention. Othersublimator-heat exchangers have been previously disclosed in US. Pat.Nos. 2,990,696; 3,170,303 and 3,197,973 among others. Thesublimator-heat exchanger 33 may be a typical sublimator consist ing ofa porous material, usually metal, with an adjacent surface of the porousmaterial exposed to a vacuum. The vacuum in the case of utilization ofthe system by an astronaut would be outerspace. In the operation of asublimator-heat exchanger 33, a liquid, usually water, is allowed tomake contact with the porous material, in the present case, water fromthe water storage unit 34. This water is fed to the sublimator portionof the sublimator-heat exchanger 33 via line 55 and valve 56. The valve56 may be closed during the time the astronaut is in the spacecraft toprevent water leakage. The water in the porous material evaporates to apoint that sufficient heat is lost and the water freezes. The water in afrozen state sublimates directly to a gas. The gas may be ventedoverboard via port 57. Since the liquid is water, then the porousmaterial surface of the sublimator maintains itself at an averagetemperature of 32 F., independent of the heat load, by itsself-controlling sublimation of the water. The device is self-regulatingbecause as the heat input to the sublimatorheat exchanger 33 rises, thevapor pressure in the sublimatorheat exchanger 33 rises and thesublimation process speeds up. Thus, heat from the liquid coolant in theclosed loop 31 may be transferred to the sublimator-heat exchanger 33.Therefore, the suit inhabitant may control the temperature of the liquidcoolant by adjusting the diverter valve 32 which controls the amount ofliquid coolant flowing through the sublimator-heat exchanger 33, whichin turn, determines the amount of heat released from the liquid coolant.

Referring now to FIGS. 2 and 3, a front view and a side view,respectively, of an astronaut within an integrated life support systemare shown. The protective suit 11 is shown with the accompanying helmet12. The breathing bag 13 is located between the protective suit 11 andthe chest and back area of the astronaut. The output 13b of thebreathing bag 13 allows gas to be fed to the helmet 12. The liquidcoolant garment 28 which covers nearly all of the body of the astronautis not shown. Also shown is the communications set 15 including theconnection 117 to the astronaut. The check valve 18 is shown connectedto the helmet which provides an outlet for the expired gas of theastronaut along with the output 44 which allows the cooled low-moisturegas to be vented into space after being circulated over the body of theastronaut. The manual control valve 22 and the diverter valve 32 areshown on the torso section of the protective suit ill, for controllingthe gas flow and water flow, respectively. Additional items shown arethe sublimatonheat exchanger 33, the compressed gas source l9, the pumpaccumulator 29, the water storage unit 33, the gas pressure gauge a, anda compartment 60 for holding the various components, for example, thecompressed gas source 19 and the pump accumulator 29. Other componentsare shown which are numbered in accordance with the block diagram ofFIG. 1.

Referring now to H0. 4, there is shown a perspective view of a backpack70 of a life support system. The backpack 70 as illustrated wouldutilize two compressed gas sources 19a and 19b, for supplying primaryand emergency ventilation requirements, respectively. Also shown arevarious other components, illustrated without connections, such as thesublimator-heat exchanger 33, the gas cooler 37, the pump accumulator29, the pulse pump 25, the water storage unit 34, the manual control 22,and the manual water control, for controlling the gas flow and waterflow, respectively.

Depending upon the requirements of the vehicle, the environment, or themission, the integrated life support system of FIGS. 2 and 3 or thebackpack arrangement of FIG. 4 may be utilized by the astronaut in aparticular operation.

Thus, although the present invention has been shown and described withreference to particular embodiments, nevertheless, various changes andmodifications obvious to a person skilled in the art to which theinvention pertains are deemed to lie within the spirit, scope, andcontemplation of the invention as set forth in the appended claims.

What is claimed is:

l. A life support system for an individual comprising:

a. an atmosphere-impervious suit enclosing said individual;

b. closed loop means secured to said suit for regulating the thermalcondition of said individuals said closed loop means including:

i. a liquid coolant garment in pressure contact with the body of saidindividual, said liquid coolant garment having an input port and anoutput port;

ii. a pump accumulator having a liquid coolant therein,

said pump accumulator having; an input port and an output port;

iii. a pulse pump having a first and second port connected to saidoutput port of said pump accumulator and said input port of said liquidcoolant garment, respectively;

iv. a sublimator-heat exchanger having a first and second port connectedto said output port of said liquid coolant garment and said input portof said p'ump accumulator, respectively, said sublimator-heat exchangerincluding a water storage unit; and

. open loop means secured to said suit for providing the ventilationrequirements of said individual, said open loop means cooperating withsaid closed loop means to insure proper regulation of the terminalcondition of said individual.

2. A life support system as recited in claim 1 wherein saidatmosphere-impervious suit comprises:

a rigid torso section;

four sections covering the extremities of said individual,

said four sections connected to said rigid torso section, said foursections having flexible joints relative to respective natural joints ofsaid individual; and

a helmet connected to the upper part of said rigid torso section so asto enclose the head of said individual, said helmet having an input portand an output port.

3. A life support system as recited in claim 2 wherein said open loopmeans comprises:

compressed gas means; and

a breathing bag having an input port and an output port,

said output port connected to said input port of said helmet, said inputport of said breathing bag adapted to receive gas from said compressedgas means, said breathing bag constructed in the shape of a vestcovering the chest and back area of said individual, said breathing bagadapted to be retained between said rigid torso section and said chestand back area of said individual so as to be compressed and inflated inaccordance with the breathing pattern of said individual.

4. A life support system as recited in claim 3 wherein said compressedgas means cooperates with said pulse pump of said closed means forensuring a flow of said liquid coolant through said liquid coolantgarment.

5. A life support system as recited in claim 4 comprising:

drying means for drying the skin surface of said individual,

said drying means having an input port and an output port, and

dehumidifying means coupled between output port of said helmet of saidsuit and said input port of said drying means for cooling anddehumidifying the expired gas of said individual.

accumulator, respectively, said sublimator-heat exchanger including adiverter means for bypassing part of said liquid coolant from enteringsaid sublimator-heat exchanger, said sublimator-heat exchanger furtherhaving 6. A life support system as recited in claim wherein said 5 asecond input port and second output port; dehumidifying means comprises:a water storage unit having a bladder interposed therein for a gascooler having an input port and an output port, said providing a firstand second compartment, said first cominput port being coupled to saidoutput port of said helpartment having an input port and said secondcompartmet; ment having an output port, said output port of said first awater separator having an input port and first and second 10 compartmentbeing connected to said second input port output ports, said input portbeing connected to said outof said sublimator-heat exchanger; put portof said gas cooler, said first output port being at least one regulatedcompressed gas source connected to connected to said water storage unitand said second outsaid second input port of said pulse pump; put portbeing connected to said first input port of said a breathing bag havingan input port and an output port drying means. connected to said secondoutput port of said pulse pump 7. A life support system as recited inclaim 6 wherein said and said input port of said helmet, respectively,said drying means comprises a network of four ducts coupled frombreathing bag constructed in the shape of a vest covering said inputport of said drying means to the responsive outer exthe chest and backarea of said individual, said breathing tremities of said individual,said ducts being capable of carrybag adapted to be retained between saidrigid torso secing the cooled, low-moisture content gas from said watertion and said chest and back area of said individual so as separator,and said output port of said drying means is located I be compressed andinflated in accordance with the in said rigid torso section of saidsuit. breathing pattern of said individual;

8. A life support system for an individual comprising: a gas coolerhaving an input port and an output port, said an atmosphere-impervioussuit enclosing said individual, input port being coupled to said outputport of said helsaid suit including a rigid torso section, four sectionscont; nected to said rigid torso section and covering the respec a Watersep tor having an input port an fir t and second tive extremities ofsaid individual, said four sections havoutpu P 1 Said input port beingconnecte t Said Opting flexible joints relative to respective naturaljoints of Put port of cooler fi output Port w said individual, and ahelmet connected to the upper part connected to and Input of Sam waterstorage mm; of said rigid torso section, said helmet enclosing the heada I 3 of said individual and having an input port and an output dryingmeans including a network of four input ducts and an pom output valve,said network of four Input ducts coupled a liquid coolant garment inpressure contact with the body 531d Secfmd output 9? Sam sePzframr ofSaid individual, said liquid coolant garment having an and saidrespective outer extremities of said lndlvldual, input port and anoutput port; said ducts adapted to carry cool, low-moisture content apump accumulator having a liquid coolant therein, said gas m fseparatoriand outPut valve bemg pump accumulator having an input portand an output 'f m 531d torso F" 9 port; 9 A l fe support system for anindividual as recited in claim a pulse pump having a first input portand first output port 8 wherein said regulated compressed gas source,said sublimaconnected to Said output port of Said Pump accumulator 0tor-heat exchanger, said gas cooler, said pump accumulator, and saidinput port of said liquid coolant garment respec said pulse pump, andsaid water storage unit are mounted in a fively, said pulse pump furtherhaving a Second input port backpack means for providing the capabilityof detaching the and a Second output port; 7 sub stantialbulky items ofsaid l fe support system when said a sublimatopheat exchanger having afirst input port and ind vidual ISIIOI required to utilize said lifesupport system first output port connected to said output port of saiddurmgapamcular liquid coolant garment and said input port of said pump

1. A life support system for an individual comprising: a. anatmosphere-impervious suit enclosing said individual; b. closed loopmeans secured to said suit for regulating the thermal condition of saidindividual''s said closed loop means including: i. a liquid coolantgarment in pressure contact with the body of said individual, saidliquid coolant garment having an input port and an output port; ii. apump accumulator having a liquid coolant therein, said pump accumulatorhaving an input port and an output port; iii. a pulse pump having afirst and second port connected to said output port of said pumpaccumulator and said input port of said liquid coolant garment,respectively; iv. a sublimator-heat exchanger having a first and secondport connected to said output port of said liquid coolant garment andsaid input port of said pump accumulator, respectively, saidsublimator-heat exchanger including a water storage unit; and c. openloop means secured to said suit for providing the ventilationrequirements of said individual, said open loop means cooperating withsaid closed loop means to insure proper regulation of the terminalcondition of said individual.
 2. A life support system as recited inclaim 1 wherein said atmosphere-impervious suit comprises: a rigid torsosection; four sections covering the extremities of said individual, saidfour sections connected to said rigid torso section, said four sectionshaving flexible joints relative to respective natural joints of saidindividual; and a helmet connected to the upper part of said rigid torsosection so as to enclose the head of said individual, said helmet havingan input port and an output port.
 3. A life support system as recited inclaim 2 wherein said open loop means comprises: compressed gas means;and a breathing bag having an input port and an output port, said outputport connected to said input port of said helmet, said input port ofsaid breathing bag adapted to receive gas from said compressed gasmeans, said breathing bag constructed in the shape of a vest coveringthe chest and back area of said individual, said breathing bag adaptedto be retained between said rigid torso section and said chest and backarea of said individual so as to be compressed and inflated inaccordance with the breathing pattern of said individual.
 4. A lifesupport system as recited in claim 3 wherein said compressed gas meanscooperates with said pulse pump of said closed means for ensuring a flowof said liquid coolant through said liquid coolant garment.
 5. A lifesupport system as recited in claim 4 comprising: drying means for dryingthe skin surface of said individual, said drying means having an inputport and an output port, and dehumidifying means coupled between outputport of said helmet of said suit and said input port of said dryingmeans for cooling and dehumidifying the expired gas of said individual.6. A life support system as recited in claim 5 wherein saiddehumidifying means comprises: a gas cooler having an input port and anoutput port, said input port being coupled to said output port of saidhelmet; a water separator having an input port and first and secondoutput ports, said input port being connected to said output port ofsaid gas cooler, said first output port being connected to said waterstorage unit and said second output port being connected to said firstinput port of said drying means.
 7. A life support system as recited inclaim 6 wherein said drying means comprises a network of four ductscoupled from said input port of said drying means to the responsiveouter extremities of said individual, said ducts being capable ofcarrying the cooled, low-moisture content gas from said water separator,and said output port of said drying means is located in said rigid torsosection of said suit.
 8. A life support system for an individualcomprising: an atmosphere-impervious suit enclosing said individual,said suit including a rigid torso section, four sections connected tosaid rigid torso section and covering the respective extremities of saidindividual, said four sections having flexible joints relative torespective natural joints of said individual, and a helmet connected tothe upper part of said rigid torso section, said helmet enclosing thehead of said individual and having an input port and an output port; aliquid coolant garment in pressure contact with the body of saidindividual, said liquid coolant garment having an input port and anoutput port; a pump accumulator having a liquid coolant therein, saidpump accumulator having an input port and an output port; a pulse pumphaving a first input port and first output port connected to said outputport of said pump accumulator and said input port of said liquid coolaNtgarment, respectively, said pulse pump further having a second inputport and a second output port; a sublimator-heat exchanger having afirst input port and first output port connected to said output port ofsaid liquid coolant garment and said input port of said pumpaccumulator, respectively, said sublimator-heat exchanger including adiverter means for bypassing part of said liquid coolant from enteringsaid sublimator-heat exchanger, said sublimator-heat exchanger furtherhaving a second input port and second output port; a water storage unithaving a bladder interposed therein for providing a first and secondcompartment, said first compartment having an input port and said secondcompartment having an output port, said output port of said firstcompartment being connected to said second input port of saidsublimator-heat exchanger; at least one regulated compressed gas sourceconnected to said second input port of said pulse pump; a breathing baghaving an input port and an output port connected to said second outputport of said pulse pump and said input port of said helmet,respectively, said breathing bag constructed in the shape of a vestcovering the chest and back area of said individual, said breathing bagadapted to be retained between said rigid torso section and said chestand back area of said individual so as to be compressed and inflated inaccordance with the breathing pattern of said individual; a gas coolerhaving an input port and an output port, said input port being coupledto said output port of said helmet; a water separator having an inputport and first and second output ports, said input port being connectedto said output port of said gas cooler, said first output port beingconnected to said input port of said water storage unit; and dryingmeans including a network of four input ducts and an output valve, saidnetwork of four input ducts coupled between said second output port ofsaid water separator and said respective outer extremities of saidindividual, said ducts adapted to carry cool, low-moisture content gasfrom said water separator, and said output valve being located in saidrigid torso section of said suit.
 9. A life support system for anindividual as recited in claim 8 wherein said regulated compressed gassource, said sublimator-heat exchanger, said gas cooler, said pumpaccumulator, said pulse pump, and said water storage unit are mounted ina backpack means for providing the capability of detaching thesubstantial bulky items of said life support system when said individualis not required to utilize said life support system during a particularmission.